rtas_poster
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Debugging Wireless Sensor Networks using Mobile Actors Rajesh Karmani and Gul Agha Open Systems Laboratory, University of Illinois at Urbana-Champaign {rkumar8,agha}@cs.uiuc.edu Forw ard and Backw ard T racking W hat bugs are w e talking about? • N ode displacem ent – Can’t do m uch except localize • N ode failure (dead or disabled) – M onitor,alert before the node com plete fails • S ensor m alfunction • S oftw are bug • N etw ork congestion • Interm ittent connectivity • Bad route Error S cenario – T oken Passing Protocol O pen Q uestions • S pecifications in term s of continuous variables that describe – S ystem ,Libraries,S ervices,Physicalphenom enon • M inim ize Logging – O bservation:S tale data is often not useful – Am ount of logs as a function of specifications? • S tructure of probe actors – Idea # 1:A pplication callgraph – Idea # 2:S pecification propositions • S cheduling of actors • A bility to detect Byzantine faults M otivation • View ing W SN as an infrastructure • Large deploym ents Large investm ent • Long-running and possibly criticalapplications • Frequent node and com m unication failures • Low bandw idth m onitor,debug and (possibly)repair W SN in situ Errors in W ireless S ensor N etworks N ode displacement W eak battery H ardw are malfunction N ode failure Softw are bug Sensor malfunction Application error Congestion Interm ittent Connectivity Bad route Environm ent factors Acknowledgements: We would like to thank Bill Donkervoet, Sameer Sundresh, Kirill Mechitov and Soumyadeb Mitra for their valuable input. “A utom ated” D ebugging • Com bination of m onitors and m obile actors – M onitors alert,salvage nodes and trigger actors • M obile actors trace (forw ard and backw ard) logged events across netw ork to find the root cause • H um an operator is criticalto constructing the actor probes – But low er the barrier for operator Previously Proposed A pproaches
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Debugging Wireless Sensor Networks using Mobile Actors Rajesh Karmani and Gul Agha Open Systems Laboratory, University of Illinois at Urbana-Champaign {rkumar8,agha}@cs.uiuc.edu. - PowerPoint PPT Presentation
Transcript of rtas_poster
Debugging Wireless Sensor Networks using Mobile ActorsRajesh Karmani and Gul Agha
Open Systems Laboratory, University of Illinois at Urbana-Champaign{rkumar8,agha}@cs.uiuc.edu
Forward and Backward Tracking
What bugs are we talking about?
• Node displacement– Can’t do much except localize
• Node f ailure (dead or disabled)– Monitor, alert before the node complete fails
• Sensor malfunction• Sof tware bug• Network congestion• I ntermittent connectivity• Bad route
Error Scenario – Token Passing Protocol
Open Questions• Specifications in terms of continuous variables that
describe– System, Libraries, Services, Physical phenomenon
• Minimize Logging– Observation: Stale data is of ten not useful– Amount of logs as a function of specifications?
• Structure of probe actors– I dea # 1: Application call graph– I dea # 2: Specification propositions
• Scheduling of actors• Ability to detect Byzantine faults
Motivation
•Viewing WSN as an inf rastructure•Large deployments Large investment
•Long-running and possibly critical applications•Frequent node and communication f ailures•Low bandwidth
monitor, debug and (possibly) repair WSN in situ
Errors in Wireless Sensor Networks
Node displacement
Weak battery
Hardwaremalfunction
Node failure
Software bug
Sensormalfunction
Application error
Congestion
IntermittentConnectivity
Bad route
Environment factors
Acknowledgements: We would like to thank Bill Donkervoet, Sameer Sundresh, Kirill Mechitov and Soumyadeb Mitra for their valuable input.
“Automated” Debugging
• Combination of monitors and mobile actors– Monitors alert, salvage nodes and trigger actors
• Mobile actors trace (f orward and backward) logged events across network to fi nd the root cause
• Human operator is critical to constructing the actor probes– But lower the barrier f or operator
Previously Proposed Approaches
